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ABSTRACT: Epstein-Barr virus (EBV) is associated with several malignant diseases including nasopharyngeal carcinoma (NPC), a common neoplasm throughout southeast Asia. Radiotherapy and chemotherapy can achieve remission, but a reemergence of disease is not uncommon. Therefore, there is a need for specific therapies that target the tumor through the recognition of EBV antigens. In NPC, latent membrane protein 1 (LMP1) and LMP2 offer the best opportunity for specific targeting since they are typically expressed and T-cell determinants in each of these proteins have been defined. We have attempted to maximize the opportunity of incorporating every possible CD4 and CD8 determinant in a single formulation. We have achieved this by generating a scrambled protein incorporating random overlapping peptide sets from EBNA1, LMP1, and LMP2, which was then inserted into a replication-deficient strain of adenovirus (adenovirus scrambled antigen vaccine [Ad-SAVINE]). This report describes the construction of this Ad-SAVINE construct, its utility in generating LMP1 and LMP2 responses in healthy individuals as well as NPC patients, and its capacity to define new epitopes. This formulation could have a role in NPC immunotherapy for all ethnic groups since it has the potential to activate all possible CD4 and CD8 responses within EBNA1 and LMPs.
Journal of Virology 10/2009; 84(1):407-17. · 5.40 Impact Factor
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Viviana P Lutzky,
Joanne E Davis,
Pauline Crooks,
Monika Corban,
Mark C Smith,
Michael Elliott,
Leanne Morrison,
Simone Cross,
David Tscharke,
Benedict Panizza,
William Coman,
Mandvi Bharadwaj,
Denis J Moss
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ABSTRACT: Nasopharyngeal carcinoma (NPC) is Epstein-Barr virus (EBV) positive in all undifferentiated cases, expressing the latency II phenotype of latent membrane proteins (LMPs) 1 and 2, in addition to EBV nuclear antigen (EBNA) 1. Several studies have attempted to treat NPC with EBV-specific cytotoxic T lymphocyte (CTL) with a partial response. To improve this therapy, there is a need to expand CTL targeted to the latency II antigens of EBV, rather than the immunodominant EBV nuclear antigens 3-6 peptides typically expanded by lymphoblastoid cells. In order to maximize the expansion of LMP-specific CTL in vitro for use in adoptive immunotherapy of nasopharyngeal carcinoma patients, we used lymphoblastoid cell lines coated with synthetic peptides corresponding to CTL determinants from the LMP proteins. We investigated several issues pertaining to the expansion of an immunologically weak CTL response, including peptide and interleukin-2 concentration, and screening assays for selecting the optimal peptide for use in expansion of LMP-specific CTL. Although screening of ex vivo peripheral blood mononuclear cells did not prove to be useful in the selection of an LMP peptide for use in CTL cultures, the peptide and interleukin-2 concentrations were critical for the maximum expansion of CTL. Therefore, it is imperative that stimulation protocols are optimized for the expansion of LMP-specific CTL.
Immunology and Cell Biology 06/2009; 87(6):481-8. · 3.66 Impact Factor
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Clinical Medicine Insights : Ear, Nose and Throat. 01/2008;
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ABSTRACT: NF-kappaB inhibitors applied to animal models of rheumatoid arthritis (RA) demonstrate the important role of NF-kappaB in the production of mediators of inflammation in the joint and their antiinflammatory effects. Because NF-kappaB is involved in the differentiation, activation, and survival of almost all cells, its prolonged inhibition might have unwanted adverse effects. Therefore, we sought to apply NF-kappaB inhibitors more specifically, targeting dendritic cell (DC) differentiation, in order to influence the outcome of the autoimmune response, rather than to produce a broad antiinflammatory effect. We tested whether DCs treated with the NF-kappaB inhibitor BAY 11-7082 and exposed to arthritogenic antigen would suppress established arthritis in C57BL/6 mice.
Antigen-induced arthritis was generated in C57BL/6 mice by injection of methylated bovine serum albumin (mBSA). After mBSA challenge, mouse knee joints were injected with antigen-exposed BAY 11-7082-treated DCs or with soluble tumor necrosis factor receptor (sTNFR). Intraarticular injection of interleukin-1 (IL-1) was used to induce disease flare.
Inflammation and erosion were suppressed in mice that received mBSA-exposed BAY 11-7082-treated DCs, but not in those that received keyhole limpet hemocyanin-exposed BAY 11-7082-treated DCs. Clinical improvement was dependent on IL-10 and was associated with antigen-specific suppression of the delayed-type hypersensitivity (DTH) reaction and switching of anti-mBSA antibody isotype from IgG2b to IgG1 and IgA. Suppression of the DTH reaction or arthritic disease was not impaired by concomitant administration of sTNFR. Suppression could be reversed with intraarticular administration of IL-1beta and could be restored by a second injection of mBSA-exposed BAY 11-7082-treated DCs.
BAY 11-7082-treated DCs induce antigen-specific immune suppression in this model of inflammatory arthritis, even after full clinical expression of the disease. Such DCs have potential as antigen-specific therapy for autoimmune inflammatory arthritis, including RA.
Arthritis & Rheumatism 08/2007; 56(7):2255-66. · 7.87 Impact Factor
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ABSTRACT: CD31 (PECAM-1) is a 130-kDa member of the immunoglobulin gene superfamily expressed on endothelial cells, platelets, and most leukocytes. This report demonstrates by Western Blot and immunofluorescence that some human melanoma and adenocarcinoma cell lines express CD31 on the cell surface. The surface expression of CD31 was regulated by cell-cell contact, being higher on sparse and spontaneously detached cells. Indeed, fixing and permeabilizing tumor cells revealed a cytoplasmic pool, which was confirmed by confocal microscopy. Some of the plasma surface molecule is endocytosed following mAb binding. Engagement of CD31 on tumor cells via domain-3 inhibited proliferation by inducing cell apoptosis. On the other hand, apoptosis does not increase CD31 expression. Overall, these results indicate that there is an intracellular pool of CD31 on some tumor cells, which modulates CD31 surface expression and its role in cancer cell growth and metastasis. Thus, the expression of CD31 and its role in cell survival in some tumor cells appears to differ from endothelial cells.
Journal of Cellular Biochemistry 09/2006; 98(5):1334-50. · 2.87 Impact Factor
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ABSTRACT: The expression of secreted protein acidic and rich in cysteine (SPARC) has been associated with the malignant progression of different types of human cancer. SPARC was associated with tumor cell capacity to migrate and invade, although its precise role in tumor progression is still elusive. In the present study, we show that SPARC produced by melanoma cells modulates the antitumor activity of polymorphonuclear leukocytes (PMN). Administration to nude mice of human melanoma cells in which SPARC expression was transiently or stably knocked down by antisense RNA (SPARC-sup cells) promoted PMN recruitment and obliterated tumor growth even when SPARC-sup cells accounted for only 10% of injected malignant cells. In addition, SPARC-sup cells stimulated the in vitro migration and triggered the antimelanoma cytotoxic capacity of human PMN, an effect that was reverted in the presence of SPARC purified from melanoma cells or by reexpressing SPARC in SPARC-sup cells. Leukotrienes, interleukin 8, and growth-related oncogene, in combination with Fas ligand and interleukin 1, mediated SPARC effects. These data indicate that SPARC plays an essential role in tumor evasion from immune surveillance through the inhibition of the antitumor PMN activity.
Cancer Research 07/2005; 65(12):5123-32. · 7.86 Impact Factor
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ABSTRACT: Dendritic cells (DCs) are the most potent antigen-presenting cells and populate many tissues where they may participate in inflammatory reactions. The infiltration of polymorphonuclear leucocytes (PMNLs) into tissues is a prominent feature of inflammation. The mechanisms of PMNL recruitment depend on chemotactic factors and adhesion molecules expressed on endothelial cells. The aim of the present study was to determine whether DCs participate in the early recruitment of PMNLs. Dendritic cells derived from peripheral blood monocytes were used for this study. PMNLs incubated with culture supernatant (CS) from untreated or from tumour necrosis factor-alpha (TNF-alpha)-treated (1 hr, 100 U/ml, 37 degrees ) monocyte-derived DCs (moDCs) had increased surface expression of both CD11b and CD18. Moreover, both untreated and TNF-alpha-treated moDCs induced PMNL chemotaxis. By blocking CXCL8, CXCL5, CXCL7 and Pan GRO (CXCL1, CXCL2, CXCL3), we observed that CXCL8/interleukin-8 might be the chemokine that induced the PMNL chemotactic activity in the CS of untreated and TNF-alpha-treated moDC. Furthermore, we investigated the regulation of CXCL8 production in moDCs by adhesion molecule engagement. Our data demonstrated that CD31, CD18, CD29 and CD49d participated in the adhesion of immature moDCs to endothelium. Moreover, engagement of domains 1-3 of CD31, but not of CD29 or CD18, decreased the production of CXCL8 by immature but not mature moDCs (which display lower CD31 levels than immature moDCs). Overall, these results suggest that DCs not only trigger a specific immune response, but also the innate immune response by recruiting PMNLs. Furthermore, our results also suggest that CXCL8 production by immature DCs might be regulated by signalling through CD31 during their migration through the vascular endothelium.
Immunology 04/2005; 114(3):375-85. · 3.32 Impact Factor
